Recent comments in /f/space

reddit455 t1_jda9rsm wrote

Reply to NASA's space nuclear power program is a hot mess by bit_map

>The NASA OIG's report [PDF] reviews NASA's Radioisotope Power Systems (RPS) program, which began in 2010 with the goal of developing next-generation power systems for spacecraft

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i wonder if they can scale the "surface model" down to fit on spacecraft... assuming they're talking about probes. 10 kilowatts is not necessary.

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https://www.nasa.gov/press-release/demonstration-proves-nuclear-fission-system-can-provide-space-exploration-power

​Kilopower is a small, lightweight fission power system capable of providing up to 10 kilowatts of electrical power - enough to run several average households - continuously for at least 10 years. Four Kilopower units would provide enough power to establish an outpost.

The prototype power system uses a solid, cast uranium-235 reactor core, about the size of a paper towel roll. Passive sodium heat pipes transfer reactor heat to high-efficiency Stirling engines, which convert the heat to electricity.

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Aeromarine_eng OP t1_jda8bc0 wrote

Reply to A New Mission Will Search for Habitable Planets at Alpha Centauri by Aeromarine_eng

A new mission will search for habitable planets at Alpha Centauri by using a satellite with a small telescope.

>Discovering exoplanets is a major technological challenge, even for large space telescopes. For a mini satellite, the task is daunting. To achieve this, the team is developing a small custom-designed space telescope capable of extremely fine measurements.

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robotatomica t1_jda78ai wrote

Reply to The Northern Lights could dazzle the skies from Washington to New York on Friday, blown by winds from a giant 'hole' on the sun by thisisinsider

Funny story, my friends had left my house super late one night and the next day they were awe-struck, describing having seen something inexplicable in the sky. Mind you, we were all atheist, but they were speaking so reverently it occurred to me they felt this was some sort of spiritual occurrence, almost like they had seen God.

I was a skeptic even then and kept asking more questions to get a better idea of what they’d seen and it became clear enough to me - “That sounds like you saw an Aurora.” They immediately shook their heads, and were insistent that couldn’t be what it was. After all, we live in the contiguous US where we basically never see them. I also didn’t think we got them down here, but it made more sense that one would anomalously occur than my buddies seeing God appear in waves of color over my house in the suburbs.

And what do you know, it was in the paper that we indeed had had the majesty of the Aurora visited upon us that night. They wouldn’t talk about it, and I never brought it up again after confirming - though I coulda strangled them for not knocking on my window to bring me outside to see it with them that night!

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EntropicallyGrave t1_jda6rvo wrote

Reply to comment by Alvsvar in How much space does it require to accommodate 1 hydrogen atom? by Alvsvar

The things we think of as "observers" are extremely complex - so we're proposing something very restrictive, when we propose that we might understand physics. We're saying that there are no artifacts of this relationship that blind us.

It's important to be aware of the known mechanics of electrons; they don't move at all like classical objects; but it is their motion from which classical motion emerges, in some sense, too

It is almost arbitrary, whether you discuss things as a space populated with stuff, or if you just discuss the stuff and its relationships with itself; the nature of space is one of unreality.

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EarthSolar t1_jda578n wrote

Reply to comment by rocketsocks in James Webb Space Telescope spies hot, gritty clouds on exoplanet with 2 suns by tkocur

It’s also really, really young, at 140 million years according to Wikipedia. Jovian worlds and brown dwarfs form hot, and at young age they can be as hot as the coolest stars at ~2000-3000 Kelvins. They cool over time, but the rate is slowed from what you’d normally expect due to gravitational contraction converting planet mass’ gravitational potential energy into thermal energy as the planet shrinks down.

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rocketsocks t1_jda2reu wrote

Reply to comment by lezboyd in James Webb Space Telescope spies hot, gritty clouds on exoplanet with 2 suns by tkocur

The planet in question is on the borderline of being almost massive enough to be classified as a brown dwarf. Just like proto-stars and brown dwarfs, planets receive a great deal of heating from accretion and gravitational contraction. And due to the square-cube law the more massive an object is the more of this energy is released and the longer it is retained because surface area grows more slowly than volume. The result is that there is a great deal of internal heat that is retained within gas giants, especially the more massive ones.

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